Pulse transit time (PTT), the interval between ventricular electrical activity and peripheral pulse wave, is assumed to be a surrogate marker for blood pressure (BP) changes. The objective of this study was to analyze PTT and its relation to BP during cardiopulmonary exercise tests (CPET). In 20 patients (mean age 51±18.4 years), ECG and finger-photoplethysmography were continuously recorded during routine CPETs. PTT was calculated for each R-wave in the ECG and the steepest slope of the corresponding upstroke in the plethysmogram. For each subject, linear and non-linear regression models were used to assess the relation between PTT and upper-arm oscillometric BP in 9 predefined measuring points including measurements at rest, during exercise and during recovery. Mean systolic BP (sBP) and PTT at rest were 128 mm Hg and 366 ms respectively, 197 mm Hg and 289 ms under maximum exercise, and 128 mm Hg and 371 ms during recovery. Linear regression showed a significant, strong negative correlation between PTT and sBP. The correlation between PTT and diastolic BP was rather weak. Bland-Altman plots of sBP values estimated by the regression functions revealed slightly better limits of agreements for the non-linear model (-10.9 to 10.9 mm Hg) than for the linear model (-13.2 to 13.1 mm Hg). These results indicate that PTT is a good potential surrogate measure for sBP during exercise and could easily be implemented in CPET as an additional parameter of cardiovascular reactivity. A non-linear approach might be more effective in estimating BP than linear regression., T. Wibmer, K. Doering, C. Kropf-Sanchen, S. Rüdiger, I. Blanta, K. M. Stoiber, W. Rottbauer, C. Schumann., and Obsahuje bibliografii
The European Southern Observatory (ESO) celebrates fifty years since the signing of its founding convention. Over the last half century, ESO has become the world's most productive ground-based astronomical observatory. The signing of the ESO Convention on October, 5, 1962 and the foundation of ESO was the culmination of the vision of leading astronomers from five European countries: Belgium, France, Germany, the Netherlands and Sweden. They had decided to join forces for the purpose of building a large telescope that would give them access to the magnificent and rich southern sky. Operating three unique and world-class observing sites in Chile (at La Silla, Paranal and Chajnantor), ESO has become a leader in the astronomical research community. To celebrate the 50th anniversary, ESO and its partners (including the Czech Republic) are organising many events and public initiatives during 2012. and Marina Hužvárová.
Národní úřad pro letectví a vesmír (National Aeronautics and Space Administration - NASA) vznikl před 50 roky, 1. října 1958, na základě zákona č. 85-568 přeměnou předchozího Národního poradního výboru pro letectví (National Advisory Committee for Aeronautics - NACA). Bezprostředním spouštěcím mechanismem vzniku této nejstarší kosmické agentury bylo vypuštění první umělé družice Země - Sputniku 1 - dne 4. října 1957 v Sovětském svazu. Tento počin v době studené války znamenal pro celý svět a zejména pro Ameriku šok. Američané byli do té doby přesvědčeni o své technické nadřazenosti a nechápali, jak je možné, že SSSR, líčený jako zaostalá země, může předběhnout USA. Americké sdělovací prostředky totiž před 4. říjnem 1957 pravidelně informovaly o plánech na vypuštění umělé družice v rámci tehdy probíhajícího Mezinárodního geofyzikálního roku (MGR). Je však třeba podtrhnout, že v té době neměly Spojené státy ucelený kosmický program, přestože idea průzkumu blízkého okolí Země se plánovala už od první poloviny padesátých let 20. století. and Antonín Vítek.
Major depressive disorder is associated with abnormal autonomic regulation which could be noninvasively studied using pupillometry. However, the studies in adolescent patients are rare. Therefore, we aimed to study the pupillary light reflex (PLR), which could provide novel important information about dynamic balance between sympathetic and parasympathetic nervous system in adolescent patients suffering from major depression. We have examined 25 depressive adolescent girls (age 15.2±0.3 y ear) prior to pharmacotherapy and 25 age/gender-matched healthy subjects. PLR parameters were measured separately for both eyes after 5 min of rest using Pupillometer PLR-2000 (NeurOptics, USA). The constriction percentual change for the left eye was significantly lower in depressive group compared to control group (-24.12±0.87 % vs. - 28.04±0.96%, p˂0.01). Furthermore, average constriction velocity and maximum constriction velocity for the left eye were significantly lower in depressive group compared to control group (p˂0.05, p˂0.01, respectively). In contrast, no significant between-groups differences were found for the right eye. Concluding, this study revealed altered PLR for left eye indicating a deficient parasympathetic activity already in adolescent major depression. Additionally, the differences between left and right eye could be related to functional lateralization of autonomic control in the central nervous system., A. Mestanikova, I. Ondrejka, M. Mestanik, D. Cesnekova, Z. Visnovcova, I. Bujnakova, M. Oppa, A. Calkovska, I. Tonhajzerova., and Obsahuje bibliografii
Ornithine carbamoyltransferase has been purified from the liver of the loggerhead turtle Caretta caretta by a single-step procedure using chromatography on an affinity column to which the transition-state analogue, d-N-(phosphonoacetyl)- L-ornithine (d-PALO), was covalently bound. The procedure employed yielded an enzyme which was purified 373-fold and was judged to be homogeneous by nondenaturing and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme showed a specific activity of 224. The molar mass of the C. caretta enzyme was approximately 112 kDa, the single band obtained by SDS-PAGE indicated a subunit molar mass of 39.5 kDa; hence, the enzyme is a trimer of identical subunits. It catalyzes an ordered sequential mechanism in which carbamoyl phosphate binds first, followed by L-ornithine. The Michaelis constants were 0.858 mM for L-ornithine and 0.22 mM for carbamoyl phosphate, the dissociation constant of the enzyme-carbamoyl phosphate complex was 0.50 mM., E. Bellocco, C. Di Salvo, G. Lagan, U. Leuzzi, E. Tellone, A. Kotyk, A. Galtieri., and Obsahuje bibliografii